If we talk about the population of the
Numenoreans, we should talk about a certain point in time. But I suppose the question asks about a maximum. Even growth rates I think would have varied widely over the years.
I tend to favor a smaller contingent of initial settlers to
Numenor. Maybe only 1000 or less, maybe 1500 or 2000, possibly up to 5000. But the
Men of
Beleriand had been largely wiped out in all the warfare, and I don't think there would have been a great remnant to settle the new island at first.
It was year 32 of the
Second Age when they reached Numenor. I cannot find it, but I believe I've read that they first landed at the site of Romenna. It's logical to me that they would have also begun the building of Armenelos. At first there would have been a lot of work to do, and a lot of land to take possession of. I think families would have been large and yet there was plenty of room for most people to spread out right along that Romenna-Armenelos corridor, either in those two towns or in farmlands just beyond. They were probably mostly farmers (read: big families - and I don't think most would wait as long as the royals to start families of their own - so I think far more than 25 generations total), though some lived in their new
cities (towns?).
The Numenoreans were granted greatly increased lifespans. I wonder... was it 100 years or more after their arrival before anyone even died? Maybe they would have become so used to the idea of living, they thought it might go on forever.
Their first king,
Elros Tar-Minyatur, lived and reigned until 442. Some other significant things happened relatively soon after. Silmarien (b. 521, corrected date) became the mother of Valandil, first Lord of Andunie, and
Numenorean ships reached
Middle Earth for the first time in 600. This indicates to me that the Numenoreans may have only just about that time begun to spread out across the island and live in all parts of it. The population had grown enough to do that. By the time of "Aldarion and Erendis" the island is largely settled, but still seems pretty pastoral.
Fast forward to 1700 when the Numenoreans intervene in the war between
Sauron and the
Elves. By then, much larger population, I would think, and still all living on the island. Lots of contact with Middle Earth, but no colonies yet.
Colonization truly begins around 1800 and significant later
dates are 2270 when
Umbar is reinforced (as mentioned above) and 2350 when Pelargir is built. In the midst of all this, "Rebellion and division of the Numenoreans begins" when Tar-Atanamir takes the sceptre in 2251.
I would think that when colonization begins, many Numenoreans view their island as 'full'. Most growth after that would be in the colonies. Birth rates have probably dropped already since those early years, and might now drop to something just slightly above 2.0. Birth rates might have been higher in the colonies - especially since there was presumably a lot more 'elbow room'.
So by the time of the Fall - there may have been far more Numenoreans living in the colonies than in Numenor itself. But some of these would have not been full Numenoreans, so how do we count them?
It's also important to realize that one million people is not really a lot, when spread out over a good-sized chunk of land. I read once what the population of England was in 1066 - and I don't recall exactly, but I think around either 3 million or 5 million (and it's now prob over 50 million - at just over 50,000 sq miles). For those in the US, think about a reasonable-sized state - even without big cities - one whose land mass is fairly close to Numenor's, and see what the population is. Minnesota is a little smaller than half, and Colorado a little larger than half, the number cited above for Numenor's area - and
the one has 5 million and the other 4.5 (and Colorado has some very sparse areas). It's easy to imagine a Numenor of 5 million that is still only sparsely populated.
So - my postulations (without doing the math of actual family sizes and average time between generations):
Year / Island Population / Colony Population
32 / 2500 / -
600 / 1,500,000 / -
900 / 3,000,000 / -
1700 / 15,000,000 / -
2350 / 20,000,000 / 10,000,000
2900 / 30,000,000 / 30,000,000
3319 / 40,000,000 / 60,000,000
3320 / - / 6,000,000*
* if only 10% survived the tsunami - but maybe it was 20,000,000 - but remember, scattered around along the
rivers of
Eriador, and along the coasts of Eriador, and what would later become
Gondor, and Umbar and further south from there - including inland dwellings.
But we can play with whatever numbers we like.
